Snakebite is a common occurrence in many parts of the world, in particular in tropical areas. The venoms of certain snakes, Crotalidae and Viperidae, cause extensive tissue damage. Often, this damage is not prevented by the use of antivenin unless it is administered immediately. Our immediate goal is to determine the chemical and pharmacological properties of toxins responsible for hemorrhage and necrosis and ultrastructural mechanism of tissue damage on envenomation. Snake venoms will be fractionated and the fractions responsible for myonecrosis, hemorrhage and renal necrosis will be investigated for their chemical and pathologic properties. We hope that our research will contribute to the long-range objective of better snakebite treatment, especially for the prevention of tissue damage. BIBLIOGRAPHIC REFERENCES: Schmidt, M.E.; Abdelbaki, Y.Z.; and Tu, A.T. (1976) Nephrotoxic Action of Rattlesnake and Sea Snake Venoms: An Electron Microscopic Study, J. Pathol., 118, 75-83. Cameron, D., and Tu, A.T. (1977) Characterization of Myotoxin a from the venom of Prairie Rattlesnake (Crotalus viridis viridis), Biochemistry, in press.